diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 7c21701ba5..202bb4a14e 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -155,7 +155,6 @@ phutil_register_library_map(array(
     'ConduitAPI_diffusion_abstractquery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_abstractquery_Method.php',
     'ConduitAPI_diffusion_branchquery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_branchquery_Method.php',
     'ConduitAPI_diffusion_browsequery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_browsequery_Method.php',
-    'ConduitAPI_diffusion_commitbranchesquery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_commitbranchesquery_Method.php',
     'ConduitAPI_diffusion_commitparentsquery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_commitparentsquery_Method.php',
     'ConduitAPI_diffusion_createcomment_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_createcomment_Method.php',
     'ConduitAPI_diffusion_diffquery_Method' => 'applications/diffusion/conduit/ConduitAPI_diffusion_diffquery_Method.php',
@@ -2615,7 +2614,6 @@ phutil_register_library_map(array(
     'ConduitAPI_diffusion_abstractquery_Method' => 'ConduitAPI_diffusion_Method',
     'ConduitAPI_diffusion_branchquery_Method' => 'ConduitAPI_diffusion_abstractquery_Method',
     'ConduitAPI_diffusion_browsequery_Method' => 'ConduitAPI_diffusion_abstractquery_Method',
-    'ConduitAPI_diffusion_commitbranchesquery_Method' => 'ConduitAPI_diffusion_abstractquery_Method',
     'ConduitAPI_diffusion_commitparentsquery_Method' => 'ConduitAPI_diffusion_abstractquery_Method',
     'ConduitAPI_diffusion_createcomment_Method' => 'ConduitAPI_diffusion_Method',
     'ConduitAPI_diffusion_diffquery_Method' => 'ConduitAPI_diffusion_abstractquery_Method',
diff --git a/src/applications/diffusion/conduit/ConduitAPI_diffusion_branchquery_Method.php b/src/applications/diffusion/conduit/ConduitAPI_diffusion_branchquery_Method.php
index 4d4bd37390..98a1b7932e 100644
--- a/src/applications/diffusion/conduit/ConduitAPI_diffusion_branchquery_Method.php
+++ b/src/applications/diffusion/conduit/ConduitAPI_diffusion_branchquery_Method.php
@@ -1,35 +1,59 @@
 <?php
 
-/**
- * @group conduit
- */
 final class ConduitAPI_diffusion_branchquery_Method
   extends ConduitAPI_diffusion_abstractquery_Method {
 
   public function getMethodDescription() {
-    return 'Determine what branches exist for a repository.';
+    return pht('Determine what branches exist for a repository.');
   }
 
   public function defineReturnType() {
-    return 'array';
+    return 'list<dict>';
   }
 
   protected function defineCustomParamTypes() {
     return array(
       'limit' => 'optional int',
-      'offset' => 'optional int'
+      'offset' => 'optional int',
+      'contains' => 'optional string',
     );
   }
 
-
   protected function getGitResult(ConduitAPIRequest $request) {
     $drequest = $this->getDiffusionRequest();
     $repository = $drequest->getRepository();
 
-    $refs = id(new DiffusionLowLevelGitRefQuery())
-      ->setRepository($repository)
-      ->withIsOriginBranch(true)
-      ->execute();
+    $contains = $request->getValue('contains');
+    if (strlen($contains)) {
+      // NOTE: We can't use DiffusionLowLevelGitRefQuery here because
+      // `git for-each-ref` does not support `--contains`.
+      if ($repository->isWorkingCopyBare()) {
+        list($stdout) = $repository->execxLocalCommand(
+          'branch --verbose --no-abbrev --contains %s --',
+          $contains);
+        $ref_map = DiffusionGitBranch::parseLocalBranchOutput(
+          $stdout);
+      } else {
+        list($stdout) = $repository->execxLocalCommand(
+          'branch -r --verbose --no-abbrev --contains %s --',
+          $contains);
+        $ref_map = DiffusionGitBranch::parseRemoteBranchOutput(
+          $stdout,
+          DiffusionGitBranch::DEFAULT_GIT_REMOTE);
+      }
+
+      $refs = array();
+      foreach ($ref_map as $ref => $commit) {
+        $refs[] = id(new DiffusionRepositoryRef())
+          ->setShortName($ref)
+          ->setCommitIdentifier($commit);
+      }
+    } else {
+      $refs = id(new DiffusionLowLevelGitRefQuery())
+        ->setRepository($repository)
+        ->withIsOriginBranch(true)
+        ->execute();
+    }
 
     return $this->processBranchRefs($request, $refs);
   }
@@ -42,6 +66,37 @@ final class ConduitAPI_diffusion_branchquery_Method
       ->setRepository($repository)
       ->execute();
 
+    // If we have a 'contains' query, filter these branches down to just the
+    // ones which contain the commit.
+    $contains = $request->getValue('contains');
+    if (strlen($contains)) {
+      list($branches_raw) = $repository->execxLocalCommand(
+        'log --template %s --limit 1 --rev %s --',
+        '{branches}',
+        hgsprintf('%s', $contains));
+
+      $branches_raw = trim($branches_raw);
+      if (!strlen($branches_raw)) {
+        $containing_branches = array('default');
+      } else {
+        $containing_branches = explode(' ', $branches_raw);
+      }
+
+      $containing_branches = array_fuse($containing_branches);
+
+      // NOTE: We get this very slightly wrong: a branch may have multiple
+      // heads and we'll keep all of the heads of the branch, even if the
+      // commit is only on some of the heads. This should be rare, is probably
+      // more clear to users as is, and would potentially be expensive to get
+      // right since we'd have to do additional checks.
+
+      foreach ($refs as $key => $ref) {
+        if (empty($containing_branches[$ref->getShortName()])) {
+          unset($refs[$key]);
+        }
+      }
+    }
+
     return $this->processBranchRefs($request, $refs);
   }
 
diff --git a/src/applications/diffusion/conduit/ConduitAPI_diffusion_commitbranchesquery_Method.php b/src/applications/diffusion/conduit/ConduitAPI_diffusion_commitbranchesquery_Method.php
deleted file mode 100644
index 4ff454f0f5..0000000000
--- a/src/applications/diffusion/conduit/ConduitAPI_diffusion_commitbranchesquery_Method.php
+++ /dev/null
@@ -1,66 +0,0 @@
-<?php
-
-/**
- * @group conduit
- */
-final class ConduitAPI_diffusion_commitbranchesquery_Method
-  extends ConduitAPI_diffusion_abstractquery_Method {
-
-  public function getMethodDescription() {
-    return 'Determine what branches contain a commit in a repository.';
-  }
-
-  public function defineReturnType() {
-    return 'array';
-  }
-
-  protected function defineCustomParamTypes() {
-    return array(
-      'commit' => 'required string',
-    );
-  }
-
-  protected function getGitResult(ConduitAPIRequest $request) {
-    $drequest = $this->getDiffusionRequest();
-    $repository = $drequest->getRepository();
-    $commit = $request->getValue('commit');
-
-    // NOTE: We can't use DiffusionLowLevelGitRefQuery here because
-    // `git for-each-ref` does not support `--contains`.
-    if ($repository->isWorkingCopyBare()) {
-      list($contains) = $repository->execxLocalCommand(
-        'branch --verbose --no-abbrev --contains %s',
-        $commit);
-      return DiffusionGitBranch::parseLocalBranchOutput(
-        $contains);
-    } else {
-      list($contains) = $repository->execxLocalCommand(
-        'branch -r --verbose --no-abbrev --contains %s',
-        $commit);
-      return DiffusionGitBranch::parseRemoteBranchOutput(
-        $contains,
-        DiffusionGitBranch::DEFAULT_GIT_REMOTE);
-    }
-  }
-
-  protected function getMercurialResult(ConduitAPIRequest $request) {
-    $drequest = $this->getDiffusionRequest();
-    $repository = $drequest->getRepository();
-    $commit = $request->getValue('commit');
-
-    // TODO: This should use `branches`. Also, this entire method's API needs
-    // to be fixed to support multiple branch heads in Mercurial. We should
-    // probably return `DiffusionRepositoryRefs` and probably merge this into
-    // `diffusion.branchesquery`.
-
-    list($contains) = $repository->execxLocalCommand(
-      'log --template %s --limit 1 --rev %s --',
-      '{branch}',
-      $commit);
-
-    return array(
-      trim($contains) => $commit,
-    );
-
-  }
-}
diff --git a/src/applications/diffusion/controller/DiffusionCommitBranchesController.php b/src/applications/diffusion/controller/DiffusionCommitBranchesController.php
index 069a353a8f..df60c0563d 100644
--- a/src/applications/diffusion/controller/DiffusionCommitBranchesController.php
+++ b/src/applications/diffusion/controller/DiffusionCommitBranchesController.php
@@ -17,26 +17,30 @@ final class DiffusionCommitBranchesController extends DiffusionController {
     $branches = array();
     try {
       $branches = $this->callConduitWithDiffusionRequest(
-        'diffusion.commitbranchesquery',
-        array('commit' => $request->getCommit()));
+        'diffusion.branchquery',
+        array(
+          'contains' => $request->getCommit(),
+        ));
     } catch (ConduitException $ex) {
       if ($ex->getMessage() != 'ERR-UNSUPPORTED-VCS') {
         throw $ex;
       }
     }
 
+    $branches = DiffusionRepositoryRef::loadAllFromDictionaries($branches);
+
     $branch_links = array();
-    foreach ($branches as $branch => $commit) {
+    foreach ($branches as $branch) {
       $branch_links[] = phutil_tag(
         'a',
         array(
           'href' => $request->generateURI(
             array(
               'action'  => 'browse',
-              'branch'  => $branch,
+              'branch'  => $branch->getShortName(),
             )),
         ),
-        $branch);
+        $branch->getShortName());
     }
 
     return id(new AphrontAjaxResponse())